Image correction in image sensing system including image sensing apparatus and image processing apparatus

• US 7,391,532 B2
• Filed: 01/30/2001
• Issued: 06/24/2008
• Est. Priority Date: 02/01/2000
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Chizawa, Noriyoshi
• Primary Examiner(s): Coles; Edward L.
• Assistant Examiner(s): Thompson; James A.
• Application Number:
  US09/772,658
• Publication Number:
  US 20010033395A1
• Time in Patent Office: 2,702 Days
• Field of Search: 358/1.9, 358/461, 358/504, 358/505, 358/509, 358/515, 358/518, 358/523, 358/406, 358/519, 358/520, 358/514, 382/274
• US Class Current: 358/1.9
• CPC Class Codes: H04N 1/6027 Correction or control of colour gradation or colour contrast H04N1/6058 takes precedence
• CPC Class Codes: H04N 1/603 controlled by characteristics of the picture signal generator or the picture reproducer

Abstract

In an image scanning system which includes an image scanning apparatus for scanning an image using a solid-state image sensing element, and an image processing apparatus, the scanned image undergoes image correction. The image scanning apparatus informs the image processing apparatus of image scan characteristic data such as linearity characteristic data unique to itself. The image processing apparatus executes a correction process of an image scanned by the image scanning apparatus using the received image scan characteristic data.

Claims

1. An image sensing system constituted by connecting an image sensing apparatus and image processing apparatus,

said image sensing apparatus comprising:

an image sensing unit adapted to sense an original and output image data of the original, wherein said image sensing unit includes an image sensor which has a plurality of photoelectric conversion element arrays for respectively photoelectrically converting light of a plurality of colors;

a shading correction unit adapted to apply shading correction to the image data output from said image sensing unit;

a storage medium adapted to hold data on image sensing characteristic including spacing between the plurality of photoelectric conversion element arrays and spatial positional deviations of the plurality of colors of pixel signals, obtained by said plurality of photoelectric conversion element arrays within a single chip of said image sensor, with respect to one of said pixel signals obtained by one of said plurality of photoelectric conversion element arrays; and

an output unit adapted to output shading-corrected image data and the data on image sensing characteristic held in said storage medium to said image processing apparatus, and

said image processing apparatus comprising;

an input unit adapted to receive the image data and the data on image sensing characteristic output from said image sensing apparatus;

a line spacing correction unit adapted to correct the image data for line deviations between the plurality of colors based on the spacing between the plurality of photoelectric conversion element arrays;

a generation unit adapted to generate image sensing characteristic correction data on the basis of the spatial positional deviations of the plurality of colors of pixel signals; and

an image sensing characteristic correction unit adapted to correct influence of an image sensing characteristic on the line-deviation-corrected image data using the image sensing characteristic correction data generated by said generation unit.

2. The system according to claim 1, wherein the image sensing characteristic is a linearity characteristic.

3. The system according to claim 1, wherein the image sensing characteristic includes a characteristic for each of a plurality of colors to be sensed.

4. The system according to claim 1, wherein the data on image sensing characteristic is output from said image sensing apparatus to said image processing apparatus upon starting up said image sensing apparatus.

5. The system according to claim 1, wherein said generation unit generates the image sensing characteristic correction data by inversely converting the data on image sensing characteristic.

6. The system according to claim 1, wherein said image sensing apparatus further comprises updating unit adapted to, when an exchangeable unit including said image sensor is exchanged, update the data on image sensing characteristic held in said storage medium in accordance with a characteristic of the unit.

7. The system according to claim 1, wherein when the data on image sensing characteristic held in said storage medium is updated, said output unit outputs the updated data on image-sensing characteristic to said image processing apparatus.

8. The system according to claim 1, wherein said image sensing apparatus further comprises an optical element which brings about a change in spatial positional deviation amount of the plurality of colors of pixel signals obtained by the plurality of photoelectric conversion element arrays of said image sensor, and

the data on image sensing characteristic includes basic data which indicates a basic amount of the positional deviation amount, and auxiliary data which indicates a change characteristic of the positional deviation amount.

9. The system according to claim 8, wherein said optical element is controlled or adjusted in accordance with a magnification of an image sensed by said image sensor.

10. The system according to claim 1, wherein the data on image sensing characteristic includes data which indicates a relationship between actual positions at which light forms images on the plurality of photoelectric conversion element arrays, and design positions thereof.

11. The system according to claim 1, wherein said image sensing apparatus further comprises an optical system for forming an original image on an imaging surface of said image sensor, and

said image sensor senses the original image.

12. The system according to claim 1, wherein said image sensor has the plurality of photoelectric conversion element arrays which are separated at a predetermined line spacing.

13. The system according to claim 1, wherein the plurality of colors are three colors including red (R), green (G), and blue (B), and the data on image sensing characteristic includes data indicating spatial deviation amounts among R, G, and B pixel signals.

14. An image processing apparatus operably connected to an image sensing apparatus, the image sensing apparatus having an image sensing unit adapted to sense an original and output image data of the original, a shading correction unit adapted to apply shading correction to the image data output from said image sensing unit, a storage medium adapted to hold data for an image sensing characteristic including spacing between the plurality of photoelectric conversion element arrays and spatial positional deviations of the plurality of colors of pixel signals, obtained by said plurality of photoelectric conversion element arrays within a single chip of said image sensor, with respect to one of said pixel signals obtained by one of said plurality of photoelectric conversion element arrays and an output unit adapted to output shading-corrected image data and the data for the image sensing characteristic held in said storage medium to said image processing apparatus, said image processing apparatus comprising:

an input unit adapted to receive the image data and the data for the image sensing characteristic output from said image sensing apparatus;

a line spacing correction unit adapted to correct the image data for line deviations between the plurality of colors based on the spacing between the plurality of photoelectric conversion element arrays;

a generation unit adapted to generate image sensing characteristic correction data on the basis of the spatial positional deviations of the plurality of colors of pixel signals; and

an image sensing characteristic correction unit adapted to correct influence of an image sensing characteristic of the line deviation-corrected image data using the image sensing characteristic correction data generated by said generation unit.